Why do most marriages end?

These are the factors most associated with marital separation, so they’re not necessarily causes but definitely worth exploring:

Large age difference between husband and wife.

Wife has a much stronger preference than her husband for a(nother) child.

Young age at marriage.

Separation of husband’s parents.

Resident children born before marriage.

Dissatisfaction with the relationship.

Low household income.

Husband is unemployed.

Wife drinks more than her husband.

One spouse smokes where the other does not.

Source: “What’s love got to do with it? Homogamy and dyadic approaches to understanding marital instability” from Paper presented at the Biennial HILDA Survey Research Conference, 16–17 July 2009, Melbourne.

Hopefully this doesn’t have you too concerned about your own relationship. If so, I’ve posted before on what science has found that can improve things: